The patent badge is an abbreviated version of the USPTO patent document. The patent badge does contain a link to the full patent document.
The patent badge is an abbreviated version of the USPTO patent document. The patent badge covers the following: Patent number, Date patent was issued, Date patent was filed, Title of the patent, Applicant, Inventor, Assignee, Attorney firm, Primary examiner, Assistant examiner, CPCs, and Abstract. The patent badge does contain a link to the full patent document (in Adobe Acrobat format, aka pdf). To download or print any patent click here.
Patent No.:
Date of Patent:
Apr. 14, 1998
Filed:
Dec. 11, 1996
George E Donaldson, Chillicothe, IL (US);
William H Lane, Chillicothe, IL (US);
Caterpillar Inc., Peoria, IL (US);
Abstract
A speed-governed lean burn engine and its fuel and air delivery apparatus are provided with a control system that monitors engine conditions, including actual speed relative to a desired speed setting, to determine which of two air to fuel ratios the engine operates with under the existing conditions: either a stoichiometric ratio or a lean-burn ratio. A stoichiometric ratio is to provide short periods of smooth and rapid response to an increased load during which NOx emissions are reduced by a three-way catalyst in the exhaust from the engine. The lean-burn ratio during other periods of operation is sufficiently lean to exhibit low NOx emissions and allows operation with low fuel consumption. The invention can be applied to improve performance of gas fueled truck engines, for example.